In recent years, in the field of semiconductor storage, the development of flash memories is particularly fast. Flash memories primarily feature the ability to keep the stored information for a long time without power and have the advantages such as high integration, fast access and the ability to be easily erased and read. Therefore, they are widely used in microcomputers, automation control and many other applications.
A flash memory is typically a memory array consisting of a number of memory cells (flash memory structures) each connected (by its gate) to a word line that is capable of both erase operations requiring a high voltage (e.g., 12 V) and read operations requiring a low voltage (e.g., 2.5 V). In order to allow these erase and read operations, a dielectric layer (coupling oxide layer) between the word line and the substrate is conventionally made relatively thick to impart a high turn-on voltage.
Thus, such conventional flash memories are associated with the issues of high power consumption, inferior durability and low operating efficiency, which make them unsuitable to be used in some applications in which low power consumption, high operating efficiency and durability are required.
Therefore, there is a need for a flash memory structure, a memory array and a fabrication method thereof which can solve the above problems.